1)
Kavpeny said:
I believe Doflamingo would win against Gear 4 Luffy
during Dressrosa, despite Luffy being stronger, mostly because of Luffy's gear 4 time limit.
OP states Fishman Island as the venue, with no temporal point of comparison, hence I assumed Dressrosa to be the time when the fight takes place, since that is when Luffy fought Doflamingo.
Also, "Luffy gets stronger after each arc" is a pretty poor argument. Pick a point of time, and make a comparative analysis for that point of time instead of dealing with variable time scenarios. By your logic, every single character in One Piece, should lose to Luffy, because, "Luffy gets stronger after each arc", and hence will beat them eventually.
2) Again, I mentioned what you said already, but also stated it to be an
arguable case of PIS, because starting off with his strongest attack is not part of Luffy's character (Luffy has never started a fight with his strongest move).
On the other hand, Doflamingo not stalling Luffy is a
definite case of PIS, since Doflamingo decided to stall him out all of 10 minutes ago, and managed to pull off the strategy successfully to boot. What the heck happened to his common sense when fighting gear 4 Luffy the second time? Instead of stalling him out and winning, he decided to take Luffy head-on? For that matter, why did Doflamingo even let Luffy transform the second time to begin with? The entire last segment of Luffy vs Doflamingo screams PIS (although it was a pretty epic end, to be honest).
As for Luffy not being at 100%, the statement is entirely true. But Doflamingo was in a much worse condition than Luffy. He tanked a Red Hawk, and a point-blank Gamma Knife, which should have been a fatal attack, by the way. I seriously doubt the weak-ass attacks from Bellamy caused more damage than an point blank Red Hawk, never mind the Gamma Knife. As for the fight in the Colosseum, Luffy didn't pull out Gear 4 or even Elephant Gatling. Not saying the Colosseum fights didn't sap his stamina, but people definitely overestimate the stamina drain from the Colosseum fights.
Like I said, quite clearly as well, I am well aware that Gear 4 Luffy (during Dressrosa) was stronger than Doflamingo. That is not a debate at all. However, being stronger is not the only way of winning a fight.
Stalling is a legitimate combat stratagem, particularly when the opposition has a time limit, and factoring in Doflamingo's awakened abilities, and the increase in stall time they provide, I'm pretty certain that a fully healthy Doflamingo would win against a healthy Luffy.